Many wafer production processes are based on plasma effects. Charged particles are used. Examples are etching processes of contacts and vias, processes structuring aluminum metal lines, and Plasma-enhanced chemical vapor deposition PECVD processes depositing inter-metal dielectrics. During the wafer processing such plasma processes can charge metal lines. If such a line is connected to the gate of a transistor in the product, the charge can cause a tunneling current through the gate oxide damaging or destroying the oxide. The damage can be in form of neutral oxide defects forming trap states in the oxides, which can be recharged by product operation during the product lifetime. With too many trap states being charged, the transistor parameters can shift so far that the product may fail during its lifetime.